Laboratory versus outdoor testing: Lactate endurance diagnostics and training management

Recording the endurance lactate concentration has for some 40 years now been considered the most sensitive parameter for identifying and differentiating the aerobic capacity in muscle metabolism. Lactate behavior or the lactate-running-speed ratio is influenced under lab conditions both by the shock absorption of the specific treadmill type, the treadmill angle of inclination, and outdoors by the ground conditions. What is decisive for both indoor and outdoor measurements is the integrative lactate behavior. For outdoor testing, a staggered stress/endurance duration that was about three times as long as the duration period used for indoor lab tests resulted in significantly lower threshold values (running speed related to a lactate concentration of 4 mmol/l or anaerobic threshold, respectively). The above methodological influences play no substantive role if the sole intention is to answer whether the athlete’s endurance has improved, deteriorated or been maintained. However, if the goal is to identify lactate-optimized training speeds for endurance runs, then the type of treadmill needs to be calibrated biologically to match the surfaces on which the athlete in question predominantly trains. More- over, increasing the staggered stress period from 3 to 8–9 min as of the intensity that triggers a significant lactate accumulation is also meaningful. Results achieved with field tests conducted under normal climatic conditions, by contrast, offer direct and precise indications for training adjustments and economic benefits, as up to eight persons can be evaluated at one and the same time in the course of 45 minutes.